This invention relates to a connector device having a plug pin and receptacle for receiving the plug pin to provide the electrical connection between the plug pin and the receptacle, and in particular to a connector device having a very small plug pin and very small receptacle for receiving the pin and adapted for use in making an electrical connection on a flat plate-like IC package.
FIG. 1 shows one form of a flat plate-like IC package 70 comprised of a body for receiving semiconductor integrated circuits, such as a memory and CPU, and connector 72 having a greater number of holes 73 in a grid-like array with each receptacle 74 located within the corresponding hole. The holes are densely formed such that, for example, 10 holes are located across the end face, 1 cm in length, of the connector. From this it will be appreciated that the respective terminals are very small in dimension.
FIG. 2 shows receptacle 74 with a plug pin detached. Receptacle 74 is comprised of cylindrical contact section 75 and external connection pin 76 extending from one end of contact section 75. The semiconductor device of IC package 70 is connected to forward end 76a of external connection pin 76. One end 78a of plug pin 78 is inserted into cylindrical contact section 75. Plug pins 78 are inserted into connector 79 as shown in FIG. 3 in which case the other end 78b of plug pin 78 is connected to, for example, a circuit of a printed circuit board. In this way, the semiconductor circuit of the IC package is connected to that of the aforementioned printed circuit board.
In connector device including connectors 72 and 79, plug pin 78 is a round bar, i.e., a bar circular in cross-section. As shown in FIG. 4, the diameter l of the cylindrical contact section 75 of the receptacle 74 is set somewhat smaller than the diameter d of plug pin 78 so that plug pin 78 is inserted into receptacle 74. Upon the repetitive insertion and withdrawal of plug pin 78 into and out of receptacle 74, the cylindrical contact section 75 encounters an external expansion force, markedly reducing the function of holding plug pin 78. At that time, plug pin 78 is worn out during the mating engagement with receptacle 74.